Do fast engagements ever work out?

It sounds like you've found your soulmate (: and I hate to say it but no, average relationships that go that fast rarely last, but then again your situation doesn't sound average. If you've been close of friends for long enough that you know what each other are thinking I think you're ready. But be warned, if you haven't lived long enough together you may find things out you didnt wanna know. So GOOD LUCK :DD